Electrophotographic copying machine of optical system-moving type

ABSTRACT

An electrophotographic machine of such type that a roll-like electrophotographic copying paper is fed into each of treating zones disposed along a copying paper transfer passage by means of a feed reel and an optical system for forming an image corresponding to an image of an original to be copied is moved on a passage for the optical system in a machine frame to effect slit exposure; wherein the electrophotographic copying paper is cut in a size corresponding to an optional exposure length of the original, and the movement of the optical system for the exposure step is complete in correscpondence to the optional exposure length of the original and simultaneously the return movement of the optical system is initiated, whereby the copying operation can be accomplished promptly without bringing about a waste of electrophotocopying paper and a loss time during the copying operation.

United States Patent Washio et al.

[ Nov. 26, 1974 TYPE Inventors: Takaji Washio; Tatsuo Aizawa, both of Osaka, Japan Assignee: Mita Industrial Company Limited,

Osaka, Japan Filed: July 16, 1973 Appl. No.: 379,340

Foreign Application Priority Data July 20, 1972 Japan 47-73087 US. Cl 355/13, 271/57, 355/3 R, 355/8, 355/14, 355/29, 355/66 Int. Cl G03g 15/00 Field of Search 355/13, 8, l4, ll, 99, 355/29, 65, 66

References Cited UNITED STATES PATENTS 10/1970 Suzuki et al. 355/13 9/1972 Hofmann et al. 355/14 X hagfd H 35 B l4; 19 20 53 Sugita et a l. 355/8 X Tanaka et al. 355/8 X 5 7 ABSTRACT An electrophotographic machine of such type that a roll-like electrophotographic copying paper is fed into each of treating zones disposed along a copying paper transfer passage by means of a feed reel and an optical system for forming an image corresponding to an image of an original to be copied is moved on a passage for the optical system in a machine frame to effect slit exposure; wherein the electrophotographic copying paper is cut in a size corresponding to an optional exposure length of the original, and the movement of the optical system for the exposure step is complete in correscpondence to the optional exposure length of the original and simultaneously the return movement of the optical system is initiated, whereby the copying operation can be accomplished promptly without bringing about a waste of electrophotocopying paper and a loss time during the copying operation.

13 Claims, 14 Drawing Figures PATENTEL HDV ZS I974 SHEET 10F 9 SHEET 3 BF 9 PATENIE NOV 2 8 I974 PATENTEL HUVZSIQM ,52

SHEEI 8 OF 9 w FGI T Wm N OWE TOP T 560 A I I I I I I II g m AT P 4 S" E N s m" M W P 3 G m s Q U Q 2 Q w E T L S R w" m T" s T t fizz. Lo Al mi; 29533 --C LOPY|NG OPERATION TIME ELECTROPHOTOGRAPHIC COPYING MACHINE OF OPTICAL SYSTEM-MOVING TYPE This invention relates to an electrophotographic copying machine. More particularly, the invention relates to an electrophotographic machine of the type wherein a roll-like electrophotographic copying paper is fed into each of several treating zones disposed along a copying paper transfer passage by means of a feed reel and an optical system for forming an image corresponding to an image of an original to be copied is moved along a passage for the optical system in the machine frame to effect slit exposure; wherein the electrophotographic copying paper is cut to a size corresponding to an optional exposure length of the original, and the movement of the optical system for the exposure step is completed in correspondence to the optional exposure length of the original and simultaneously the return movement of the optical system is initiated, whereby the copying operation can be accomplished promptly without bringing about a waste of electrophotocopying paper and a loss of time during the copying operation.

In conventional electrophotographic copying machines of the type wherein a roll-like electrophotographic copying paper is fed into each of several treating zones disposed along a copying paper transfer passage by means of a feed reel and an optical system for forming a light image corresponding to an image of an original to be copied is moved along a passage therefore in a machine frame to effect slit exposure, a series of operations such as cutting the copying paper, stopping the movement of copying paper at a prescribed exposure position, transfer of the optical system for the exposure step, return of the optical system, and transfer of copying paper from the exposure zone to the development zone are performed, and it is generally difiicult to perform these operations smoothly without a time loss.

It is therefore a primary object of this invention to provide an electrophotographic copying machine of the above type in which an optional exposure length of an original to be copied is prescribed and the operations of cutting of copying paper and of transferring the optical system for the exposure step are completed in correspondence to said optional exposure length to simultaneously initiate the return travel of the optical system, whereby the above-mentioned series of the operations can be performed smoothly without a time loss.

Another object of this invention is to provide an electrophotographic copying machine of the abovementioned optical system-moving type in which control of the above-mentioned series of the operations can be accomplished precisely by means of a detecting mechanism of a relatively simple structure.

Still another object of this invention is to provide an electrophotographic copying machine with a compact optical device of the moving type in which the height and length of the optical device can be greatly diminished as compared with conventional optical devices and a sufficient optical distance can be secured even if the height and length of the optical device is thus diminished, whereby the bulk of the copying machine as a whole can be reduced.

A still further object of this invention is to provide an electrophotographic machine in which the weight of an optical device is diminished and travel and stop of the optical device can be accomplished smoothly.

A still further object of this invention is to provide an electrophotographic copying machine including a light quantity-adjusting device of a simple structure, in which the exposure width (slit width) of a moving type optical device can easily be adjusted by operating a light quantity adjusting member mounted at any desired location on the copying machine, whereby a de-' sired light quantity can optionally be obtained.

A still further object of this invention is to provide an electrophotographic copying machine having an exposure adjusting device which is especially effective for the continuous copying operation, in which an improper exposure can be corrected instantaneously by observing a finished copy even when an optical device is traveling in the exposure step,

A still further object of this invention is to provide an electrophotographic device of the optical systemmoving type in which the treatment time required for each step in the copying machine is detected and when this actual detected time becomes longer than the prescribed time, a trouble-detecting mechanism is actuated to detect trouble caused at the copying paper transfer passage or the optical device travel passage, whereby continuous occurrence of the trouble or aggrevation of the trouble can be effectively prevented.

A still further object of this invention is to provide an electrophotographic copying machine of the optical system-moving type, in which steps are conducted continuously in succesion and when trouble is caused at any step, occurrence of the trouble can be promptly detected.

Other objects and advantages of this invention will be apparent from the description given hereinafter.

In accordance with this invention, there is provided an electrophotographic copying machine which cornprises a passage for transfer of electrophotographic copying paper including a zone for a device for feeding a roll-like electrophotographic copying paper, a zone for a device for cutting the roll-like electrophotographic paper, a zone for a charging device, a light exposure zone, a zone for a developing device and a zone for a drying or fixing device. These zones are disposed along said passage in the order recited above. A transparent plate is mounted in the upper portion of a machine frame to support thereon an original to be copied, an optical system for connecting said transparent plate optically with said passage for transfer of electrophotographic copying paper and forming an image corresponding to an image of the original on the electrophotographic copying paper at said light exposure zone, and an optical system-moving passage for traveling the optical system between said passage for transfer of electrophotographic copying paper and said transparent plate. A mechanism for determining an optional exposure range and a corresponding cut length of the copying paper is mounted in the machine frame; optical system-detecting means for detecting the moving optical system is mounted in said optical systemmoving passage and first copying paper forward enddetecting means is mounted in said copying paper transfer passage to detect the forward end of the moving copying paper. The optical system-detecting means and first copying paper forward end-detecting means are so disposed that they are interlocked with each passage. Second copying paper forward end-detecting means is mounted in said zone for light exposure of the copying paper so that when the forward end arrives at a position for initiation of the light exposure, said detecting means detects this arrival and stops the movement of the copying machine. The copying papercutting device is actuated by a signal transmitted from said first copying paper forward end detecting means to cut the copying paper into a length corresponding to said determined optional exposure range of the original. The optical system is so driven that thetravel of the optical system for the light exposure step is initiated by a signal transmitted from said second copying paper forward end-detecting means which is actuated when the forward end of the copying paper arrives at a position for initiation of the light exposure and the return travel of the optical system is initiated by a detecting signal transmitted by said optical system-detecting means, whereby the light exposure step of the optical system is completed in correspondence to the length of said determined optional exposure range of the original.

This invention will now be illustrated detailedly by reference to embodiments shown. in the accompanying drawings, in which members having the same function are indicated by common referential numerals.

FIG. 1 is a sectional side view illustrating arrangement of devices and mechanisms in one embodiment of the electrophotographic copying machine of this invention.

FIG. 2 is an enlarged side view showing a curlremoving mechanism in the electrophotographic copying machine shown in FIG. 1.

FIG. 3 is an enlarged front view showing the curlremoving mechanism illustrated in FIG. 2.

FIG. 4-A is an enlarged sectional side view illustrating an optical system in the electrophotographic copying machine shown in FIG. 1.

FIG. 4-B is a partially cut-out, side view illustrating arrangement of a light quantity-adjusting mechanism of the optical system shown in FIG. 4-A.

FIG. 4-C is a partially enlarged sectional view illustrating the front of the mechanism shown in FIG. 4-B.

FIG. 4-D is a side view illustrating arrangement of another embodiment of the light quantity-adjusting mechanism shown in FIG. 4-C.

FIG. 5 is a view illustrating arrangement of a drive mechanism in the electrophotographic copying machine shown in FIG. 1.

FIG. 6 is a view illustrating the plane section of a drive mechanism for change-over of the optical system.

FIG. 7 is a side view illustrating arrangement of detecting means in the electrophotographic copying machine of this invention.

FIG. 8 is a perspective view illustrating an embodiment of a mechanism for determining the exposure range and cut length of copying paper in the electrophotographic copying machine of this invention.

FIG. 9 is a wiring diagram of the electric system in the electrophotographic copying machine of this invention.

FIG. 10 is a wiring diagram illustrating the principle of a trouble-detecting means adaptable to the electrophotographic copying machine of this invention.

FIG. 11 is a graph illustrating the detecting principle of the trouble-detecting means shown in FIG. 10.

In FIG. 1 illustrating an outline of an embodiment of the electrophotographic copying machine of this invention. In the interior of a machine frame 1 there is provided a passage b for transfer of electrophotographic copying paper, which includes a feed reel 2 fitted with a roll of electrophotographic copying paper 3, a zone 4 for provision of a device for cutting electrophotographic copying paper, a zone 4' having a device for removing curls from copying paper, a zone 5 having a charging device, a light exposure zone 6, a zone 7 wherein a developing device is provided and a zone 8 wherein a drying or fixing device is located, these zones being disposed along said passage b in the order recited above.

The feed reel 2 is attached dismountably and freely rotatably to the end portion of the machine frame 1, namely on the left side end portion in the drawings, and the reel 2 can easily be taken out of the machine frame 1 by opening a lid 9 mounted on the left end wall of the machine frame 1. A guide roller 10 is disposed below the feed reel 2 to remove copying paper 3 from the reel 2, and a pair of paper-feeding drive rollers 11 and 11 equipped with a paper feed clutch G which is actuated when the copying operation is initialed are disposed between the guide roller 10 and the copying paper-cutting device zone 4.

A fixed blade 12 and a rotary blade 13 are positioned in the copying paper-cutting device zone 4. The rotary blade 13 is rotated by means of a cutter solenoid RS, whereby the copying paper 3 passing between the fixed blade 12 and rotary blade 13 is cut.

It is preferred that a curl-removing mechanism 14 for removing curls from the copying paper 3 and smoothing the paper surface be mounted between the copying paper-cutting device zone 4 and charging device zone 5. As illustrated enlargedly in FIGS. 2 and 3, this curlremoving mechanism comprises a pair of segment rollers l5 and 15' disposed with a certain distance therebetween, a small-diameter roller 16 disposed to contact the peripheral surface of each of segment rollers 15 and 15', and guides 18 disposed in voids 17 formed in notched portions of segment rollers 15 and 15' in a manner such that each of the guides 18 is positioned between of the axes of segment rollers 15 and 15' and the axis of the small-diameter roller 16 while not contacting the peripheral surface of the small-diameter roller 16. The segment rollers 15 and 15' are disposed on the same side as the axis of the reel 2 with respect to the copying paper transfer passage b, namely on the upper side of the passage b in the drawings, and the small-diameter rollers 16 is disposed on the opposite side with respect to the passage b, namely on the lower side of the passage b in the drawings. The copying paper 3 having curls is at first nipped at a nip point n between the segment roller 15 and small-diameter roller 16, introduced into a space defined by a triangle formed by linking the axes of the three rollers, and withdrawn from a nip point n between the segment roller l5 and small-diameter roller 16. At this time, the plane for forwarding the copying paper 3 in the above triangular space is defined by the periphery of the small-diameter roller 16 having a curvature opposite to that of the copying paper 3. Since the curly copying paper 3 is forwarded while supported on the periphery of the small-diameter roller 16, removal of curls can be accomplished effectively. The guide 18 functions to prevent the copying paper 3 from winding on one segment roller and also guide the paper to the nip point n betweenthe other segment roller 15' and the smalldiameter roller 16. It is preferred that either or both of the segment rollers 15 and 15' and the small-diameter roller 16 are positively driven at a peripheral speed which is the same as the speed at which the copying paper 3 travels. When rollers of the curl-removing mechanism 14 are driven in this manner, it is possible to allow the curl-removing mechanism to serve as the discharge side drive rollers of the copying papercutting device zone 4 and as the feed side drive rollers of the charging device zone 5.

The charging device zone 5 on the discharge side of the curl-removing mechanism 14 comprises shield cases 19 and 19' and fine wire corona discharge electrodes 20 and 20' spread in the shield cases. The copying paper 3 is electrically charged while it is forwarded through a passage formed between said shield cases 19 and 19.

The light exposure zone 6 disposed on the discharge side of the charging device zone 5 comprises a transfer endless belt 21 for supporting and horizontally forwarding the copying paper 3 and for stopping the movement of the copying paper 3. This transfer endless belt 21 is supported and driven by a drive pulley 22 equipped with a clutch C, which is not actuated during the light exposure step, a drive pulley 23, and guide pulleys 24 and 24. A suction case 21' is disposed below the upper part of said endless belt 21, and air suction is effected by a sucking fan 21" mounted in a blast duct connected to said suction case 21, whereby the horizontal support of the copying paper is ensured.

A driven press roller 28' is disposed above the feed side drive pulley 23 so as to have a contact with the pulley 23 through the belt 21, and a driven press roller 22' is disposed above the discharge side drive pulley 22 so as to have a contact with the pulley 22 through the belt 21.

On the discharge side of the drive pulley 22 and press roller 22, there is provided a developing device indicated as a whole by reference numeral 7. The zone 7 of the developing device includes a tank 25 for a liquid developer 0, an upper tray 26 disposed above the tank 25 and a lower tray 27. A development passage 28 is formed between the upper and lower trays 26 and 27, and the copying paper is allowed to pass through this passage 28. The liquid developer 0 contained in the tank 25 is drawn up into the upper tray 26 by means of a pump (not shown) and flows into the development passage 28 to effect the development. A pair of squeeze rollers 29 and 29' are disposed on the discharge side of the development passage 28 to squeeze out excessive liquid developer applied to the copying paper. On the discharge side of said squeeze rollers 29 and 29, a zone 8 of a drying or fixing device is disposed. This drying or fixing device zone 8 comprises a heating cylindrical roller 30 having a heater H and a confronting roller 31 facing the roller 30. When the developed copying paper passed through between said rollers 30 and 31, the drying or fixing is effected in the copying paper,

and the copying paper is withdrawn to a copying paper receiver 32 disposed outside the machine frame.

The exhaust gassucked by the suction fan 21" is introduced into an air duct 30' through blower duct and blown on the developed copying paper at the copying paper receiver 32. In this manner, the exhaust gas assists the drying of the copying paper.

In a preferred embodiment of the copying machine of this invention illustrated in FIG. 1, the copying paper transfer passage b extending from the paper-feeding drive rollers 11 and 11' to the development passage 28 is disposed substantially horizontally and the curlremoving mechanism 14 is mounted on the feed side of the charging device zone 5. Accordingly, jamming of the copying paper in the copying paper transfer passage or exposure of the copying paper in the curly or bent state can be effectively prevented. Further, since a part of the copying paper transfer passage b extending from the development passage 28 to the drying or fixing device zone 8 is inclined so that the inclination is substantially in accord with the tangent line on the curved periphery of the development passage 28, jamming of the copying paper at this part of the copying paper transfer passage, can be effectively prevented, and this feature, together with the specific structure of the optical system detailed hereinafter, makes it possible to shorten the size of the copying machine in the lengthwise direction and makes the structure of the copying machine compact.

In the electrophotographic copying machine illustrated in FIG. 1, in order to perform copying paper feeding not only by manual feeding of a sheet-like copying paper 3', a feed inlet 33 for the sheet-like copying paper 3' is mounted in the lower portion of the machine frame 1 on the side where the feed reel 2 is contained. A pair of drive rollers 34 and 34 for feeding the sheet-like copying paper 3' and confronting guide plates 35 and 35' defining a passage b for the sheetlike copying paper 3' are disposed between the feed inlet 33 and the feed side of the curl-removing mechanism 14. In this manner, on the feed side of the charging device zone 5, the passage b for the manually fed sheet-like copying paper can be formed independently from the passage b for the automatically fed roll-like copying paper 3.

A transparent plate 36 for supporting thereon an original a to be copied is fixed on the upper surface portion of the machine frame 1, and a press plate 37 for pressing the original a on the transparent plate 36 is attached to the upper portion of the machine frame 1 by means of a hinge 38 or a similar member. This transparent plate 36 for supporting the original a and the copying paper exposure zone are disposed in a corresponding relationship with a certain distance therebetween. In the space between this transparent plate 36 and the copying paper exposure zone 6, there is mounted an optical system 39 for optically connecting the transparent plate 36 with the copying paper exposure zone 6 and for forming on the copying paper 3 a light image corresponding to the image of the original a. The optical system travels along a passage 40.

The optical system indicated as a whole by numeral 39 includes a light source 41 for exposure, an opening 42 for exposing the original to light, a group of reflection mirrors 43, 44 and 45, an in-mirror lens 46 and an opening 47 for exposing the copying paper to light. Each of these members is attached to a frame 48 so that each member can move simultaneously reciprocatingly along the moving passage 40. It is preferred that these the members 41, 43, 44 45 and 46 form, together with the frame 48, an encircled room defining substantially the outer wall of the optical system 39. Light shielding curtains 50 and 50 allowing the reciprocating movement of the optical device 39 are disposed between both side end wall portions of a chamber containing therein the optical device 39 and moving passage 40 and between both side portions of the optical device 39, respectively. At both side portions of the chamber 49, winding reels 51 and 51 are disposed to wind the light-shelding curtains 50 and 50', respectively. The winding reels 51 and 51 are supported so that they can rotate in either clockwise or counter-clockwise direction, and a force for winding the curtain 50 or 50 is given to each of the reels 51 and 51' by means of an elastic member such as a spring (not shown). Thus, each of the curtains 50 and 50' is always spread between the optical device 39 and the winding reel 51 or 51. When the optical device 39 moves, for instance, toward the right in the drawings, since the lightshielding curtain 50 is stretched, the winding reel 51 is rotated in the clockwise direction to reel off the lightshielding curtain in a length necessary for compensation for the stretching, and since the other lightshielding curtain 50 is relaxed, the winding reel 51 is rotated in the clockwise direction to wind the excessive length of the curtain 50'. When the optical device 39 moves toward the left in the drawings, the winding reels 51 and 51' are rotated in the counter-clockwise direction and perform functions opposite to those mentioned above, respectively.

In an especially preferred embodiment of the optical device 39 of this invention, as shown in FIG. 4-A, the in-mirror lens 46 is disposed above the frame 48 in a manner such that an optical path x of the in-mirror lens 46 is substantially perpendicular to the moving direction of the frame and the in-mirror face is positioned on the upper side. The original exposure opening 42 and copying paper exposure opening 47 are disposed so that an optical path x of the opening 42 and an optical path x;; of the opening 47 are substantially perpendicular to the moving direction of the frame 48. A first reflection mirror 43 is mounted along the optical path x of the in-mirror lens 46, a second reflection mirror 44 is mounted along the optical path x of the original exposure opening 42, and a third reflection mirror 45 is mounted along the optical path x of the copying paper exposure opening 47. The first reflection mirror 43 is' disposed in the state inclined with to the optical path x, by an angle of about 45 in the clockwise direction. The second reflection mirror 44 is inclined with respect to the optical path x by an angle of 135 1 6, 0 to in the clockwise direction (hereinafter angles are those in the clockwise direction unless otherwise indicated). Thus, the in-mirror lens 46 and the original exposure opening 47 are optically connected to each other through the first reflection mirror 43 and the second reflection mirror 44. The third reflection mirror 45 is inclined with respect to the optical path x by an angle of 45 i 0 (0 0 to 10), whereby the in-mirror lens 46 and the copying paper exposure opening 47 are optically connected with each other through the first reflection mirror 43 and the third reflection mirror 45.

In the optical device 39 illustrated in FIG. 4-A, the optical path x of the original exposure opening 42 is positioned between the optical path x, of the in-mirror lens 46 and the optical path x of the copying paper exposure opening 47 and each of these optical paths is substantially perpendicular to the moving direction of the frame 48. The optical path x, of the in-mirror lens 46 is disposed in the discharge side of the copying machine; the second reflection mirror 44 on the optical path x is disposed in the lowermost position of a optical device 39 and the third reflection mirror 45 on the optical path x is disposed in the position higher than the position of the second reflection mirror 44. Moreover the second reflection mirror 44 is disposed at. an angle deviated from by 0 and the third reflection mirror 45 is disposed at an angle deviated from 45 by -H9 In order to make the optical device 39 compact and diminish the size of the copying machine, it is indispensable that each of the above positional relationships be established. In short, when the above structure is adopted in the optical device 39, the height and length of the optical device 39 can be greatly diminished as compared with optical devices of conventional copying machines, and further, even if the size of the optical device 39 is thus diminished, it is possible to maintain a sufficient optical distance. Furthermore, by thus diminishing the capacity of the optical device 39, it is possible not only to diminish the capacity of the copying machine as a whole but also to halt the optical device 39 in a space SP (see FIG. 1) formed above the developing device zone 7 and the drying or fixing device zone 8 or in a space SP (see FIG. 1) formed above the charging device zone 5 when the optical device 39 is at the position for initiation of the exposure step or at the position for completion of the exposure step. Accordingly, the fatal defect of conventional copying machine of this exposure system, i.e., the defect that the dimension or size of the copying machine in the lengthwise direction is extremely large can be effectively eliminated in the copying machine of this invention. Still further, since each member of the optical device is so disposed that members of'the optical device form an outer wall of the optical device, the weight of the optical device is reduced and the movement of the optical device and the stopping thereof can be accomplished very smoothly.

In the copying machine of this invention, as the moving passage 40 for the optical system 39 there may be employed an optical member as far as it can move the optical system 39 horizontally in the lengthwise direction. As an instance of a member having such mechanism, there can be mentioned a combination of a pinion and a rack and a combination of rails and rotars or wheels.

In FIG. 5 illustrating an embodiment of the drive system of the copying machine of this invention, a guide rail 53 is attached'to the machine frame 1 through supporting washers 53' and 53" in a manner such that the rail 53 extends above the copying paper exposure zone 6 horizontally in the lengthwise direction. The optical system 39 is supported on said guide rail 53 through rotors or wheels 54 so that it can move horizontally in a reciprocating manner. The optical system 39 is driven by an optical system-driving mechanism capable of reversing of the moving direction of the optical system and is moved reciprocatingly along the guide rail 53. The optical system-driving mechanism can be, for instance, a combination of a drive drum 55 rotatable in both the normal and reverse directions and a wire 56, such as shown in FIG. 5. More specifically, the wire 56 is wound on the drive drum 55, and one end of the wire 56 is fixed to a wire-fixing member 58 of the optical device 39 through a reel 57 pivoted at one end of an optical system-containing chamber 49 of the machine frame 1. The other end of the wire 56 is fixed to a device member 58 of the optical deivce 39 through a reel 57 pivotally mounted on the frame 1 in chamber 49.

As is enlargedly illustrated in FIG. 6, electromagnetic clutch mechanisms C and C having, respectively, sprockets 60' and 60, each being driven by a drive chain 59, are mounted on the machine frame 1. A rotary disc C of the electromagnetic clutch mechanism C the drive drum 55 and a sprocket 61 are pivoted on one shaft 62, and a rotary disc C of the electromagnetic clutch mechanism C and a sprocket 61' are pivoted on a shaft 62. A chain 63 is hung between sprockets 61 and 61, and both the shafts 62 and 62 are rotated in the same direction. Sprockets 60 and 60' are rotated in the directions reverse to each other at the same speed by means of a chain 59. In this manner, by actuation of the change-over mechanism, an electric current is applied to the electromagnetic clutch mechanism C and when a current is cut off in the electromagnetic clutch mechanism C a clutch plate 60,, of the sprocket 60 is bound to the rotary disc C by a magnetic force, whereby the drive drum 55 is rotated in the same direction as that of the sprocket 60 and the optical device 39 is moved woard the left, namely in the course for the exposure step, by means of the wire 56. At this time, also the sprocket 61 and shaft 62 are rotated via the sprocket 61 and chain 63, but since a current is cutoff in the electromagnetic clutch mechanism C the sprocket 61 is rotated idly with respect to the shaft 62. Then, by switching of the change-over mechanism, an electric current is applied to the electromagnetic clutch mechanism C while a current is cut off in the electromagnetic clutch mechanism C the sprocket 60' and shaft 62 rotating in the direction opposite to the rotation direction of the sprocket 60 are bound to each other electromagnetically in the same manner as described above, and they cause the drive drum 55 to rotate in the direction opposite to the direction in the above-mentioned case through the sprocket 61, chain 63, sprocket 61 and shaft 62. Thus, the optical device 39 is moved by the wire 56 in the opposite direction (in the right direction), namely in the return course. Also in this case, the sprocket 60 is similarly rotated idly with respect to the shaft 62.

The change-over or reversal of the direction of the horizontal reciprocating movement can be accomplished by the above-mentioned procedures. When the number of gears of sprockets 61 and 61' are appropriately changed, it is possible to make the speed of the return course of the optical device 39. higher than the speed of the optical device 39 in the course for the light exposure step. In this invention, it is preferredthat the speed of the optical device 39 in the return course be equal to, or greater than, the speed of the optical device 39 in the course for the light exposure step. It is possible to move the optical device 39 horizontally in the reciprocating manner by employing, instead of the above-mentioned combination of the drive drum 55 and drawing wire 56, a plurality of drive rotors equipped with an electromagnetic clutch and being rotated in reverse directions to one another.

In the copying machine of this invention, it is preferred that an exposure adjusting mechanism, which can adjust the exposure amount even when the optical device is moving, be provided. For instance, as is illustrated in FIGS. 4-B and 4-C, a shutter plate is disposed on the lower side edge of the optical device so that the width of a slit of the copying paper exposure opening 47 is adjusted. The shutter plate 125 is fixed on a shaft 125 is fixed on a shaft 126 rotatably coupled to both the 'side walls of the optical device 39 so that the plate can rotate around the shaft 126. A shutter plate-rotating arm 129 having at its end a movably mounted member for instance, a block 128 rotatably mounted on a shaft 127, is fixed on one end of said shaft 126. The shaft 126 is rotated by moving the arm 129-to thereby rotate the shutter plate 125, and the slit width is thus adjusted.

Any of modifications of the above-mentioned mechanism can be used as the light exposure adjusting mechanism, as far as it can adjust the exposure amount in the state interlocked with the above-mentioned movably mounted member.

In the optical device 39, in addition to the above movably mounted member, i.e., the block 128, at least one fixedly mounted member is provided. For instance, blocks 131 and 131' are rotatably attached to shafts 130 and 130' fixed on the side wall of the optical device 39, respectively.

A member forming a path passing through the fixedly mounted block 131, the movably mounted block 128 and the fixedly mounted block 131 in this order, for instance, a wire 132, is spread between both ends of the moving passage of the optical device 39, and one end of the wire 132 is fixed and supported on one side frame 1' of the machine frame 1 by means of a pin 133 at a position outside the standard position P1 fixed on one end of the moving passage 40 so that the standard position P1 is not changed regardless of the movement of the optical device 39. In this case, it is also possible to fix one end of the wire 132 at the standard position P1. The other end of the wire 132 is once supported by a block 135 rotatably mounted on a shaft 134 fixed to the other side frame 1" of the machine frame 1, through the standard position P2 fixed on the other end of the moving passage 40 so that the standard position P2 is not changed regardless of the movement of the optical device 39, and the other end of the wire 132 is then fixed to the machine frame 1, preferably a light exposure adjusting member 136 so designed that it can be operated from outside of the machine. In this case, said other end of the wire 132 may be fixed on the light exposure adjusting member 136 at the standard position P2 without being supported by the block 135.

An elastic member 138 such as a spring is hung between the shutter plate-rotating arm 129 and the side wall of the optical device 39 to stretch the spread wire 132 and keep it always under tension, whereby a force is given to the movably mounted block 128.

Thus, the length l of a line extending from the standard position P1 to the standard position P2 is changed by adjustment of the light exposure adjusting member 136.

The mode of spreading the wire 132 may be appropriately changed depending on the arrangement of said movably mounted member and said fixedly mounted member.

In the foregoing embodiment of the invention, in addition to the above-mentioned wire, other known members such as a belt, a chain, a rope and the like can be used as the line member, and a suitable member is selected as the member for changing the direction of the path of the line within element 39 depending on the kind of the line member actually used. For instance, fixed rods, blocks, gears and the like can be employed.

In the embodiment shown in FIG. 4-B, the light exposure adjusting member 136 is so designed that the adjustment is accomplished by sliding it on a guide rail 137, but any member capable of changing the line length I can be employed. For instance, a rotary thumbscrew may be employed.

In the embodiment shown in FIG. 4-B, during the adjustment of the light exposure, when the light exposure adjusting member 136 is moved in the direction indicated by an arrow, the wire 132 is stretched and the length l of the line extending from the standard position P1 fixed on one end of the moving passage 40 to the standard position P2 fixed on the other end of the moving passage 40 is changed, whereby the movably mounted block 128 is shifted to the point indicated by the two-dot chain line against the force of the elastic member 138, and the positional relationship of the movably mounted block 128 to the fixedly mounted blocks 131 and 131 is changed. Accordingly, the shaft 126 is rotated and the shutter plate 125 fixed on the shaft 126 is rotated so that the slit width is opened, as indicated by the two-dot chain line.

Thus, as is illustrated in FIG. 4-C, when the members 128, 131 and 131 and both the standard positions P1 and P2 are so fixed as to define a path having a certain length, the once-fixed positional relationship of the movably mounted, member 128 to the fixedly mounted, members 131 and 131 is not substantially changed even if the optical device 39 is moved along the moving passage 40 to effect the light exposure unless the light exposure adjusting member 136 is shifted from the fixed position, and in contrast, even if the optical device 39 is moved for light exposure, the light exposure amount can be optionally adjusted by changing the above positional relationship and, accordingly, the path length, by shifting the light exposure adjusting member 136.

The arrangement of the above-mentioned pathlength changing members can be accomplished in vari' ous manners. For instance, as is diagrammatically illustrated in FIG. 4-D, only one fixedly mounted, member, e.g., a block 131, may be employed.

In the embodiment illustrated in FIG. 4-D, when the light exposure adjusting member 136 is shifted in the direction indicated by an arrow to the point indicated by the two-dot chain line and the wire 132 is stretched, the shutter plate-rotating arm 129 having a movably mounted block 128 is rotated with the shaft 126 as the center to the point indicated by the two-dot chain line against the force of the elastic member 138, whereby the positional relationship between the movably mounted block 128 and fixedly mounted block 131 (and the path length) is changed. As a result, the shaft 126 is rotated and the shutter plate 125 fixed on the shaft 126 is rotated as indicated by the two-dot chain line to close the slit width.

As in the embodiment shown in FIG. 4-B, in the embodiment of FIG. 4-C the once-adjusted positional relationship between the movably mounted, member 128 and the fixedly mounted, member 131 is not substantially changed even if the optical device 39 is moved along the passage 40 to effect the light exposure. For attaining this feature, members 128 and 131 and both the standard positions P1 and P2 are so fixed as to form a path.

In the above embodiment of this invention having a very simple structure, it is possible to obtain an optional exposure amount by adjusting the shutter plate simply by operating the light exposure adjusting member, and further, the adjustment of the slit width can be accomplished very easily even if the optical system is moved for the light exposure step. Accordingly, in case a number of copies are continuously obtained from one original, compensation for an improper exposure can be accomplished optionally at any time while the finished condition of copies are being observed. This is one of advantages of the above embodiment of the invention. Further, when a plurality of originals differing in the proper exposure amount are copied, as soon as light exposure of one original is completed, a light exposure amount suitable for the next original can be set. Thus, the time required for the copying operation is shortened, which is another advantage of this embodiment.

In the copying machine of this invention, it is indispensable that while theexposure of copying paper is conducted, the copying paper 3 should be kept stationary in the light exposure zone 6 and no additional copying paper 3 should be fed into the exposure zone 6. It is also indispensable that in the developing device zone 7 and the drying or fixing device zone 8, the copying paper 3 should move continuously. For attaining these features, for forward mechanism of the copying paper transfer passage in the developing device zone 7 and the drying or fixing device zone 8 is always driven while the forward mechanism of the copying paper transfer passage running through the exposure zone 6, the charging device zone 5 and the paper feed mechanism is so constructed that it can be optionally driven or stopped.

To return to the embodiment shown in FIG. 5, a drive chain 59 is hung on a sprocket 64 mounted through a clutch C on the shaft on which the pulley 22 of the exposure zone 6 is positioned, a sprocket 65 fixed on one roller 29 of a pair of squeeze rollers 29 and 29 in the developing device zone 7 and a sprocket 66 fixed on one roller 31 of a pair of heating rollers 30 and 31 in the drying or fixing device zone 8, as well as on the sprockets and 60' of the above-mentioned optical system-driving mechanism. When this drive chain 59 is driven by a sprocket 67 attached to a drive motor M, the foregoing sprockets 64, and 66 are continuously rotated and during the operation of the copying machine, squeeze rollers 29 and 29 and heating rollers 30 and 31 are continuously driven.

A sprocket 68 and a double sprocket 69 are pivoted on the drive pulleys 22 and 23 of the exposure zone 6, respectively, and a chain 70 is hung on said sprocket 68 and one side of said double sprocket 69.

A drive chain 74 is hung on the other side of the double sprocket 69, a sprocket 71 for driving segrnentrol- A lers 15 and 15 of the curl-removing mechanism 14, a sprocket 72 attached through the paper feed clutch C on the shaft on whichone of paper-feeding drive rollers 11 and 11, and a sprocket 73 pivoted on one of a pair of sheet-like copying paper feed rollers 34 and 34'. The

clutch C, has the same structure and function as those Y of clutches C and C illustrated above by reference to FIG. 6. When the clutch C is not actuated, the sprocket 64 is being rotated idly with respect to the drive pulley 22 and sprocket 68. Accordingly, drive chains 70 and 74 and transfer endless belt 21 are not driven but remain stationary. When the clutch C is actuated, the drive pulley 22 and sprocket 68 are driven, and simultaneously, the chain 70, drive pulley 23, double sprocket 69, chain 74 and sprockets 71, 72 and 73 are driven, whereby the endless belt 21 in the exposure zone 6, each of rollers 15, and 16 of the curlremoving mechanism 14 and the sheet-like copying paper feed rollers 34 and 34' are driven accordingly.

Feed rollers 11 and 11' for feeding roll-like copying paper are driven only when the sprocket 72 is driven and the paper feed clutch C is actuated. As illustrated above, the driving of the optical device 34 is performed by driving sprockets 60 and 60 by the chain 59 and actuating the direction change-over clutches C and C alternately.

In the electrophotographic copying machine of this invention, on conducting the electrophotographic copying, by actuating the paper feed clutch C,, a pair of paper-feeding drive rollers 11 and 11 are rotated, whereby the a roll-like paper 3 is unwound from the feed reel 2, and it passes through the copying papercutting device zone 4 and reaches the curl-removing mechanism 14 in which the paper 3 is uncurled. Then, the uncurled copying paper is driven by rollers 15, 15 and 16 of the curl-removing mechanism and fed into the changing device zone 5. The copying paper 3 is allowed to pass through corona discharge electrodes 20 and 20', between which a high electric voltage is applied. The corona discharge from the electrodes 20 and 20 is applied to the photoconductive layer of the moving copying paper 3, whereby uniform charges are applied to the photo-conductive layer of the copying paper 3. The thus uniformly changed copying paper 3 is gripped between the drive pulley 23 and press roller 23 and placed on the transfer belt 21. When the copying paper arrives at the'prescribed position of the exposure zone 6, the operation of the clutch C is stopped to halt the movement of either the transfer belt 21 or the chains 70 and 74 (whereby the movement of the entire paper feed system is stopped). The cutting of the roll-like copying paper is accomplished by rotating the rotary blade 13 of the copying paper-cutting device zone 4 by actuating a cutter solenoid RS in in response to the exposure range length of the original.

' Then, the clutch C for moving the optical system in the left direction is actuated to rotate the drive drum 55 in the clockwise direction, whereby the optical device 39 is shifted to the left and the moving slit exposure is effected. More specifically, by illumination from the exposure light source 41, a light reflected from an original a be the copied passes through the transparent plate 36, original light exposure opening 42, second reflection mirror 44 and first reflection mirror 43 and arrives at the in-mirror lens 46. Then, the light is reflected on the in-mirror 52, passes through lens 46, first reflection mirror 43, third reflection mirror 45 and copying paper light exposure opening 47 and arrives at the copying paper 3 to form thereon a light image corresponding to the image of the original a. This slit exposure operation is performed along the prescribed exposure range length of the original a, with the result that an electrostatic latent image corresponding to the image of the original a is formed on the photoconductive layer of the copying paper '3. After completion of the light exposure step, the clutch C, is actuated to drive the transfer endless belt 21, whereby the electrostatic latent image-carrying copying paper 3 is introduced to the subsequent development passage 28, where the copying paper 3 is coated with a liquid developer c and a visible image corresponding to the electrostatic latent image is forrned on the copying paper 3. Then, the visible image-carrying copying paper is fed between a pair of perpetually driven squeeze rollers 29 and 29 to remove the excessive liquid developer, and it is fed between a pair of perpetually driven heating rollers 30 and 31 to effect the drying or fixation of the developed image. Then, the copying paper is expelled onto on a copying paper receiver 32. Separately, after completion of the light exposure step, the optical device 39 is shifted to the right, namely in the return course, by stopping the operation of the direction change-over clutch C and simultaneous actuation of the clutch C to rotate the drive drum 55 in a countclockwise direction. In the case of sheet-like copying paper, the feeding of copying paper is similarly accomplished by feeding the sheet-like copying paper 3' through the feed inlet 33 whereupon it is gripped between a pair of drive rollers 34 and 34'.

Most important features of the electrophotographic copying machine of this invention reside in that a mechanism for determining the cut-length of copying paper in correspondence to the prescribed optional light exposure range length of an orignal 'to be copied (hereinafter referred to merely as determining mechanism) is mounted in the copying machine frame 1. Detecting means for detecting the optical system 39 is provided on the moving passage 40 for the optical system and a first copying paper forward end-detecting means for detecting the forward end of the moving copyirfg paper is provided on the copying paper transfer passage b, and these two detecting means are so arranged thatthey can be interlocked with each other in response to instructions of said determining mechanism and move along the optical system-moving passage 40 and copying paper transfer passage b. A second copying paper forward end-detecting means is mounted on the copying paper transfer passage b in the exposure zone 6, and each of the means is interlocked and controlled so that the operations of cutting the copying paper, halting the copying paper in the exposure zone, initiating the travel of the optical system for the light ex posure step, terminating the light exposure step of the optical system initiating the return travel of the optical system and of shifting the copying paper from the exposure zone to subsequent zones can be conducted smoothly without a loss of time and accurately in correspondence to the prescribed exposure range length of the original by signals transmitted by said detecting means.

In order to embody the foregoing important feature, the foregoing detecting means and other members are arranged in the electrophotographic copying machine of this invention in such a manner as illustrated in FIG.

7. In an embodiment shown in FIG. 7, a determining mechanism (dial) for determining the cut-length of the copying paper in correspondence to the prescribed optional exposure range is mounted on the side wall of the machine frame 1. This detennining dial 75 can be rotated to determine an optional light exposure range length or cut-length Lx within a range from a minimum light exposure range length or minium cut-length Lmin to a maximum light exposure range length or maximum cut-length Lmax. As is shown in the perspective view of FIG. 8, the dial 75 has on the periphery thereof graduations 76 ranging from the minimum light exposure range length graduation Mmin to the maximum light exposure range length graduation Mmax. When an arrow mark 77 is set on a dial graduation corresponding to a desired light exposure range length or cutlength Lx, the light exposure range length and the copying paper cut-length are prescribed and determined. In order to facilitate the determination of the optical light exposure range length and the copying paper cut-length according to the length of an original a to be copied, graduations 78 ranging from the minimum exposure range length M'min to the maximum exposure range length Mmax can be formed on the side edge of the upper surface of the machine frame on which the transparent plate 36 is fixed, whereby the setting of the position of the dial 75 can be performed with ease by determining a desired exposure range length based on graduations 78.

To return to the embodiment of FIG. 7, according to this invention, an optical system-detecting means S4 for detecting the moving optical device 39 is mounted on the optical system-moving passage 40 and a first copying paper forward end-detecting means S1 for detecting the forward end of the moving copying paper 3 is mounted adjacent on the copying paper transfer passage b. These detecting means S4 and S1 are so arranged that they are interlocked with each other in response to instructions of the determining mechanism 75 and move along the optical system-moving passage 40 and copying paper transfer passage b, respectively. For this movement of the detecting means S4 and S1, for instance, as is shown in FIG, 7, a loop 79 of a chain, wire or code is disposed so that one side of the loop 79 extends along the optical system-moving passage 40 and another side of the loop 79 extends along the copying paper transfer passage b in the light exposure zone 6. This loop 79 is wound on a drum 75' of the determining mechanism 75 and is supported by guide pulleys 80, 81 and 82. This loop 79 can be moved in an optional direction by rotating the determining mechanism (dial) 75.

A supporting member 83 for the optical systemdetecting means S4 is fixed to the side portion 79 of the loop 79 that extends along the optical systemmoving passage 40, while a supporting member 84 for the first switch mechanism S1 is fixed to the side portion 79" of the loop 79 that extends along the copying paper transfer passage b. The optical system-detecting mechanism S4 is attached tothe upper portion of the supporting member 83 and the lower portion 83' of the supporting member 83 is fitted on a suitable guide rail, for instance, an optical system-guiding rail 53, for movement along this rail. The optical system-detecting means S4 consists, for instance, for a change-over switch having a push plate 85. When the push plate 85 is pressed by a part of the optical device 39, for instance, a projection 86, the optical device is detected by the detecting means S4. The first copying paper forward end-detecting means S1 is attached to the upper portion of the supporting member 84 fixed on the side portion 79" of the loop 79, and the lower portion 84 of the supporting member 84 is mounted on a guide rail 87 for movement along said guide rail 87.

Also this first copying paper forward end-detecting means S1 may be, for instance, a change-over switch having a push plate 88. When this push plate 88 is pressed by the forward end of the copying paper, detection of the forward end of the copying paper is accomplished.

In the apparatus shown in FIGS. 1, 5 and 7, when the dial of the determining means is turned, the optical system-detecting mechanism S4 is moved along the optical system-moving passage 40 and the first copying paper forward end-detecting means S1 is moved along the copying paper transfer passage b. The loop 79 is arranged so that if the optical system-detecting means S4 is moved to the right the first copying paper forward end-detecting means S1 is moved to the left, namely the means S1 and S4 are moved in directions opposite to each other. This is important in order to make the position for initiation of exposure of the copying paper correspond precisely to the position for initiation of exposure of the original.

In the copying machine of this invention, when the determining mechanism 75 is set to the graduation Mmin, the first copying paper forward end-detecting means S1 is positioned on the leftmost point (Pmin in FIG. 7) and the optical systemdetecting means S4 is positioned on the rightmost point (Pmin in FIG. 7). In case the determining mechanism 75 is set to the graduation Mmax, the first copying paper forward enddetecting means S1 is positioned at the rightmost point (Pmax in FIG. 7) and the optical system-detecting means S4 is positioned at the leftmost point P'max. In this case, the following relation should be established among distances bl 1 and bl of the copying paper transfer passage b extending from the contact point PC of the fixed blade 12 and rotary blade 13 in the copying paper-cutting device zone 4 to the above-mentioned points Pmin and Pmax, respectively; the distances al and al of the optical system-moving passage 40 extending from the point P'S for initiation of the original exposure step to the above-mentioned points Pmin and P'max, respectively; and the above-mentioned Lmin and Lmax:

bl nLrnin,

bl nLmax,

al Lmin a, and

a]; Lmax a, wherein (1 indicates the over-run length necessary for completely exposing the original a and n is the magnification of the copy relative to the original. Since the value of n is usually 1, it is preferred that bl, and bl are equal to Lmin and Lmax, respectively. It is sufficient that the value of a is equal to the exposure slit width of the optical system, namely the width d of the original exposure opening 42 of the optical system 39. Of course, it is possible to employ a delay electric circuit while the value of a is fixed to zero. In this case, after a certain time-lag from the detection of the optical system by the optical system-detecting means S4, namely after a time t necessary for the optical system to travel along said distance d has passed from the detection of the optical system by the detecting means S4, the exposure step is completed.

In the copying machine of this invention, when the forward end of the copying paper 3 presses the push plate 88 of the copying paper forward end-detecting means S1, the switch S1 is actuated and in response to the signal transmitted by this switch S1 an electric current is applied to the cutter solenoid RS, whereby the cutter solenoid RS is actuated to rotate the rotary blade 13 to cut the copying paper 3. In this case, since the distance bl between the push plate 88 of the first copying paper forward end-detecting means S1 and the operation point PC of the copying paper cutting device 4 is always kept equal to the prescribed exposure range length Lx, a precise cut-length of copying paper can be attained and indirect mechanisms for controlling the cut-length of copying paper, provision of which is indispensable in conventional copying machines, need not be provided in the copying machine of this invention.

The actuation of the cutter solenoid RS is performed, for instance, by an electric circuit shown in FIG. 9. A push button PB for initiation of the copying operation, a normally closed contact a of a switch S1 and an offdelay R are connected in series to the electric source, and a paper feed clutch C is connected to the electric source in parallel to the off-delay relay R The normally open contact l-lb of the off-delay relay R the normally closed contact 2-3 of a relay R and a relay R are connected in series to the normally open contact b of the switch S1. The cutter solenoid Rs is connected to the electric source in series to the normally open contact 3-1 of the relay R When the push button PB is pushed and electric current is allowed to pass therethrough, the paper feed clutch C is actuated to effect the feeding of a roll-like copying paper. Simultaneously, the relay R is actuated and the usually open contact l-lb is closed. When the forward end of the copying paper presses the switch S1, the normally open contact b of the switch S1 is closed to actuate the relay R Simultaneously, the normally open contact 3-1 of the relay R is closed to actuate the cutter solenoid RS. After sufficient time has passed for the cutter solenoid to accomplish the cutting of the copying paper, the normally closed contact a of the switch S1 is opened, whereby the nonnally open contact l-lb of the offdelay relay R, is opened and the operation of the cutter solenoid RS is stopped. When the forward end of the copying paper actuates the switch S1 and the normally closed contact a of the switch S1 is opened, the operation of the paper feed clutch C is automatically stopped.

To return to FIG. 7, in the copying machine of this invention, in the copying paper exposure zone 6, there is mounted a second copying paper forward enddetecting means S2 for detecting the forward end of the copying paper when it reaches the position for initiation of light exposure of the copying paper (rightmost point PS in FIG. 7). This second copying paper forward end-detecting means S2 may also be a change-over switch having a push plate 89. When the push plate 89 is pressed by the forward end of the copying paper, the switch S2 is actuated. According to this invention, the switch S2 is so disposed that when this switch S2 is pressed by the forward end of the copying paper 3 and actuated, the copying paper is stopped in the exposure zone 6 and the travel of the optical system 39 for the light exposure step is initiated. For this purpose, there is provided an electric circuit such that when the switch S2 is pressed, the actuation of the transfer clutch C in the exposure zone 6 is stopped and the clutch C of the optical system-driving mechanism is actuated to initiate the movement of the optical system for the light exposure step.

In, FIG. 9, a normally open contact b of the switch S2 of the second copying paper forward end-detecting means, normally closed contact 6-2aof a relay R and relay R are connected in series to the electric source, and the transfer clutch C is connected to normally closed contact 5-2 of the relay R When the forward end of the copying paper presses the push plate 89 and actuates the switch S2, the normally open contact b of the switch S2 is closed to actuate the relay R whereby the normally closed contact 5-2a of the relay R is opened and an electric current is cut off in the transfer clutch C with the result that the movement of the transfer belt 21 is stopped and the forward end of the copying paper is halted at the position PS for initiation of the light exposure process. The clutch C2 for return travel of the optical system is connected to the normally closed contact side a of the contact 54, and the clutch C for moving the optical system for the light exposure step is connected to the normally open contact side b of the contact 54. To a common terminal 0 of the contact 54 of the relay R are connected in series a usually open contact 5-3 of the relay R and a normally closed contact a of the contact 4-2 of the relay R.,. In the above arrangement, when the forward end of the copying paper presses the push plate 89 of the second detecting means and'actuates the switch S2, the relay R is actuated to close the contact 5-3 and close the normally open contact side b of the contact 54, whereby the clutch C for moving the optical system for the light exposure step is actuated. Thus, the movement of the optical device 39 for the light exposure step is performed by mechanisms and members detailed above by reference to FIG. 6. According to this invention, by the signal transmitted from the second copying paper forward end-detecting means mounted at the position PS for initiating the exposure of the copying paper, the stopping of the forward end of the copying paper at the exposure-initiating position and the initiation of the movement of the optical system for the exposure step can be performed simultaneously with certainty without a time delay. As is illustrated in FIG. 7,

it is preferred that a second optical system-detecting 7 means S3 be mounted so that when the optical device 39 is positioned at the light exposure step-initiating point PS, the means S3 detects the optical device 39. This optical system-detecting means S3 may also be a change-over switch having a push plate 90 and the change-over switch is so arranged that when the push plate 90 is pressed by projection 86 of the optical device 39, it is actuated. This switch S3 is connected to the common terminal C of the contact 54 of the relay R in parallel to the series circuit of the usually close contact 4-2 and usually open contact 5-3.

According to this invention, when the optical device travels for the light exposure step along the distance Lx a corresponding to the prescribed exposure range length, the detection of the optical device 39 is performed by the optical system-detecting means S4 and responsive to the signal of the detection, completion of the movement of the optical device 39 for the light exposure step (namely stopping of actuation of the clutch C and initiation of the return travel of the optical dey vice 39 (namely actuation of the clutch C can be simultaneously accomplished. More specifically, in FIG. 9, the normally open contact b of the switch S4 of the optical system-detecting means and the delay R are connected in series to the electrical source, and therefore, when the push plate 85 of the switch S4 is pressed by the projection 86 of the optical device 39, the normally open contact b of the switch S4 is closed to actuate the relay R to open the normally closed contact 6-2a in the circuit of the relay R whereby no electric current is applied to the relay R As a result, in a relay contact 5-4 connected to a parallel circuit of the optical system moving clutches C and C the change-over from the side of the clutch C, for moving the optical system for the light exposure step (b side of the contact 5-4) to the side of the clutch C for moving the optical system in the return course (a side of the contact 5-4) is effected, and an electric current is applied to the clutch C for the return travel of the optical system through the normally closed contact a and the relay switch 5-4a. Thus, actuation of the clutch C and deactivation of the clutch C are accomplished, and the return travel of the optical device 39 is performed according to the mechanisms detailed by reference to FIG. 6. On initiation of the return travel of the optical system, the switch S4 is opened, but by providing a selfretention series circuit consisting of a normally open contact b of the switch S2 and a self-retention contact 6-2b of the relay 6 in the parallel to the normally open contact b of the switch S4, the self-retention of the relay 6 is established while the copying paper is halted at the position of the switch S2, i.e., the point- PS.

When the switch S4 of the optical system-detecting means is actuated to open the relay R and actuate the relay R the copying paper transfer clutch C connected to the electric source through the normally closed contact 5-2 of the relay R and the normally open contact 6-3 of the relay R is actuated again, whereby the copying 'paper 3 which has completed the light exposure step is forwarded to the developing device zone 7 by means of the transfer belt 21.

When the optical device 39 has completed the return travel and arrives at the position P'S for initiation of the light exposure process, the projection 86 of the optical device 39 presses the push plate 89 of the second optical system-detecting means S3 to open the normally closed contact a of the switch S3 in the circuit including the optical system-moving clutches C and C whereby the optical device 39 is halted at this position P'S.

According to this invention, as detailed above, the operation for cutting the copying paper to a length precisely corresponding to the prescribed light exposure range length Lx and the moving slit exposure operation in dependence on the cut-length of the copying paper can be accomplished with certainty. Further, as illustrated above, initiation of the return travel of the optical device 39 and re-transfer of the copying paper from the light exposure position can be simultaneously accomplished concomitantly with completion of the movement of the optical device 39 for the light exposure step, and therefore, the copying operation can be highly accelerated. In fact, according to this invention, it is possible to perform so-called continuous printing operation where a plurality of copying papers are present on the copying paper transfer passage b of the copying machine. This continuous printing operation is performed in the order explained below byproviding a seriescircuit consisting of a usually opencontact 6-4 of the relay R and a switch S7 for continuous copying operation in parallel to the push button PB for initiation of copying operation, connecting a series circuit consisting of a normally open contact 6-1 and a relay R and including a self-retention circuit 2-1, to the normally closed contact a side of a relay contact l-l of the circuit of the relay R and connecting the normally open contact 2-2 of the relay R to the usually closed contact a of the switch S1 in parallel. Thus, in this invention, since the distance between two successively fed copying papers can be greatly shortened and by dint of this advantage as well as the above-mentioned advantage of shortening of one copying cycle of the lightexposure step and the return travel, the copying operation can be highly accelerated.

As illustrated above, in the copying machine of this invention, the following three different driving operations are performed:

.i. The copying paper transfer operation for feeding the copying paper into the copying paper transfer passage b, by the feeding mechanism, charging it while it is moved and stopping it in the exposure zone.

ii. The optical system-moving operation for moving the optical system for the light exposure step while the copying paper is stationary in the exposure zone. 1

iii. The copying paper transfer operation for transferring the copying paper from the exposure zone and forwarding it to the development and drying or fixing zones to effect the development and the drying I or fixation while the copying paper is being moved.

In the above copying paper transfer operations (i) and (iii), a problem relating to jamming of copying paper may exist. In the optical system-moving operation (ii),

a problem exists that is the optical system is halted mid- I way in its travel and a high power lamp is kept lighted,

resulting in super-heating of the optical system and the original.

Accordingly, it is desired that problems of continuous occurrence of paper jamming and super-heating of the optical system and the original be overcome by prescribing time periods necessary for accomplishing such operations as the transfer of the copying paper and the movement of the optical system and promptly detecting disorders when such operations are not completed within such prescribed times.

In order to attain the above object, normally open switch means are provided so that the following three treatment times can be precisely detected by these switch means respectively. Namely, each of the normally open switches is actuated upon initiation of the corresponding treatment, the actuated state is maintained during the treatment, and the switch is opened upon completion of the treatment.

' l. The time during which the feeding of copying paper is initiated and the copying paper is stopped in the exposure zone (the time for paper-feeding and charging operations).

2. The time during which the optical system initiates, in the lamp-lighted state, the movement for the light expsure step and completes the light exposure step. 

1. An electrophotographic copying machine which comprises a machine frame defining a passage for the transfer of electrophotographic copying paper, a zone for a device for feeding a roll-like electrophotographic copying paper, a zone for a device for cutting the roll-like electrophotographic paper, a zone for a device for charging said paper, a light exposure zone, a zone for a device for developing exposed paper and a zone for a device for drying or fixing developed paper, said zones being disposed along said passage in the order recited above; a transparent plate mounted in the upper portion of said machine frame to support thereon an original to be copied; an optical system optically connecting said transparent plate with the passage for the transfer of electrophotographic copying paper and forming an image corresponding to an image of the original on the electrophotographic copying paper at said light exposure zone, said optical system being movably disposed between said passage and said transparent plate; means for controlling an optical scan range and a corresponding cut length of the copying paper operatively mounted in the machine frame; optical systemdetecting means for detecting the moving optical system and movably mounted intermediate said passage and said transparent plate; first copying paper forward end-detecting means movably mounted in the copying paper transfer passage to detect the forward end of the moving copying paper, said optical systemdetecting means and first copying paper forward end-detecting means being interlocked with each other for movement along the copying paper transfer passage; second copying paper forward enddetecting means movably mounted in said passage in the light exposure zone so that when the forward end arrives at a position for initiation of the light exposure, said detecting means detects this arrival and stops the movement of the copying machine; a paper cutting device disposed in the corresponding zone and coupled to said first copying paper forward enddetecting means and actuated by a signal transmitted from said first copying paper forward end detecting means to cut the copying paper into a length corresponding to a determined optical exposure scan range of the original; and means for moving the optical system and operatively coupled thereto, whereby the travel of the optical system for light exposure is initiated by a signal transmitted from said second copying paper forward enddetecting means, actuated when the forward end of the copying paper arrives at a position for initiation of the light exposure, and return travel of the optical system is initiated by a detecting signal transmitted by said optical systEm-detecting means, whereby the light exposure is completed in correspondence to the length of said determined optical exposure scan range of the original.
 2. An electrophotographic copying machine set forth in claim 1 further comprising: a continuously driven transfer mechanism provided along said passage adjacent said developing device zone and said drying or fixing device zone; a transfer mechanism disposed along the zone for light exposure of electrophotographic copying paper and operatively coupled to said second copying paper forward end-detecting means and said optical system detecting means for stopping the driving operation of said transfer mechanism by actuation of said second copying paper forward end-detecting means to hold the copying paper in a stationary state and for restarting the driving operation of the intermittent transfer mechanism by a detection signal transmitted from said optical system-detecting means; a paper feed clutch positioned in the feeding zone; and a cutter solenoid positioned in said zone for cutting and coupled to said optical system detecting means, whereby at the time of initiation of the copying operation the paper feed clutch is actuated to effect the paper feed operation and, by a detection signal transmitted by said optical system-detecting means, the cutter solenoid is actuated and the operation of the paper feed clutch is stopped.
 3. An electrophotographic copying machine set forth in claim 2 wherein the continuous transfer mechanism includes a plurality of pulleys, at least one of which is driven through a clutch mechanism, and an endless belt which is moved and stopped in the horizontal direction by said pulleys, a suction case being mounted below the lower side of the upper part of said endless belt to ensure the support of the copying paper by the endless belt.
 4. An electrophotographic copying machine set forth in claim 2 further comprising a curl-removing mechanism positioned adjacent said passage and having a pair of segment rollers disposed with a small distance therebetween, a small-diameter roller disposed to contact with the peripheral surface of each of said segment rollers, and guides for copying paper, said guides being disposed in voids formed in notched portions of the segment rollers without contacting the peripheral surface of said small-diameter roller such that each of the guides is positioned between each of the axes of said segment rollers and the axis of the small-diameter roller, said segment rollers being disposed on the same side as the axis of a copying paper reel with respect to the copying paper take-out side and said small-diameter roller being disposed on the opposite side.
 5. An electrophotographic copying machine set forth in claim 2 further comprising means for feeding sheet-like copying paper comprised of a pair of paper-feeding drive rollers and operatively positioned for feeding paper into said machine for insertion into said roll-like copying paper transfer passage upstream of said charging device zone.
 6. An electrophotographic copying machine as set forth in claim 1 wherein said means for moving said optical system is comprised of an optical system-driving mechanism for moving reciprocatingly said optical device along said optical system-moving passage, said optical system-driving mechanism including a pair of drive clutches actuated alternately, one of said clutches driving in the normal direction a drive power transfer mechanism for transferring a drive power to the optical device and the other clutch driving said power transfer mechanism in the reverse direction.
 7. An electrophotographic copying machine as set forth in claim 6 wherein said movable optical device comprises a housing having an opening for light exposure of the original and an opening for light exposure of the copying paper, a light source for light exposure of the original, a group of reflection mirrors and an in-mirror lens, each of said members of the optical device being mounted on said housing which iS disposed for reciprocating movement along said passage, said in-mirror lens being disposed above said housing in a manner such that an optical path of the in-mirror lens is substantially perpendicular to the moving direction of the housing, being thus vertical, the in-mirror face being positioned on the upper side, and a first reflection mirror mounted on the substantially vertical optical path of said in-mirror lens, a second reflection mirror mounted on a substantially vertical optical path of the opening for light exposure of the original and a third reflection mirror mounted on a substantially vertical optical path of the opening for light exposure of the copying paper, said in-mirror lens and said reflection mirrors having such a positional relationship that said in-mirror lens is optically connected with each of the openings for light exposure through the first reflection mirror and one of the second and third reflection mirror.
 8. An electrophotographic copying machine set forth in claim 7 wherein said members of the movable optical device form, together with said housing, an encircled room defining substantially the outer wall of the optical system, light shielding curtains allowing the reciprocating movement of the optical device being disposed between both side end wall portions of a chamber containing therein the optical device.
 9. An electrophotographic copying machine as set forth in claim 1 wherein said optical device comprises at least one fixedly mounted guide member, a movably guide mounted member and a light adjusting mechanism capable of adjusting the light admitted for light exposure and interlocked with said movably mounted guide member, a member forming a line passing through said fixedly mounted guide member and said movably mounted guide member and being coupled between both ends of the path of travel of the optical device and having a first length when so arranged, one end of said line-forming member being fixed and supported on the machine frame at one of a standard position P1 fixed on one end of said moving passage and at a position outside the standard position P1 and the other end of the line-forming member being fixed at one of a second standard position P2 fixed on the other end of the moving passage and at a position passing through said second standard position P2 to a light quantity adjusting mechanism for changing the first length (l) of the line extending through said position P1 to said position P2, and said movably mounted guide member being given such a force as perpetually stretching said line-forming member under tension and the positional relationship between said fixedly mounted guide member and said movably mounted guide member being set by changing the line length (l) by said light adjusting mechanism, whereby said positional relationship is not substantially changed even if the optical device moves along its path of travel.
 10. An electrophotographic copying machine set forth in claim 9 wherein said guide member is composed of a block.
 11. An electrophotographic copying machine as set forth in claim 1 wherein a loop is disposed in the machine frame in a manner such that one side of said loop extends along the copying paper transfer passage and another side of said loop extends along the path of travel of said optical system, said loop being disposed so that it can move in an optional direction in response to an input signal, optical system-detecting means comprised of a switch having a push plate capable of engaging the optical system and mounted on the side of the loop extending along the path of travel of said optical system, and said first copying paper forward end-detecting means comprised of a switch having a push plate capable of engaging the forward end of the copying paper and positioned along the copying paper transfer passage.
 12. An electrophotographic copying machine as set forth in claim 11 wherein said loop is operatively coupled to and moves in response to input signals from said Means for controlling an optical scan range in a manner such that the distance between the actuation point of the copying paper-cutting device zone and the first copying paper forward end-detecting means is substantially equal to the distance between the position for initiation of the light exposure step of the optical device and the position at which the optical device is detected by said optical device-detecting means.
 13. An electrophotographic copying machine as set forth in claim 1, further comprising: first normally open switch means actuated at the time of initiation of feeding of copying paper and operation of which continues while the copying paper is moved and stops when the copying paper is halted in the exposure zone; second normally open switch means actuated at the time of initiation of the movement of the optical system for light exposure and operation of which continues during the travel of the optical system and stops when the movement of the optical system for light exposure is completed; and third normally open switch means actuated at the time when the copying paper is introduced in the development zone and drying or fixation zone and operation of which continues while the copying paper travels through said zones along said passage and stops when the paper passes through said zones, said normally open switch means being connected in parallel; a timer connected in series to a circuit including said normally open switch means, said timer automatically returning to its operation-initiating point when the operation of the timer is stopped and said timer including a trouble-detecting means which is actuated when said timer continues its operation for a predetermined time, and wherein each of said normally open switch means and said timer are disposed in such a relationship that when switching from one step supervised by a switch means to a subsequent step the operation of the normally open switch means or the timer is stopped and said trouble-detecting means is actuated when the timer continues its operation for a time longer than the longest time among times necessary for completion of said steps. 